Unlock expanded I/O for your MS3Pro ULTIMATE ECU.

The MS3Pro ULTIMATE Black Center Harness is an 8-foot flying lead harness designed specifically for the third (black) AMPSEAL connector on the MS3Pro ULTIMATE ECU. This harness expands your available I/O by nearly 50%, enabling advanced functionality such as boost control, VVT, traction control, flex fuel, table switching, and more.

The harness features a pre-crimped, sealed 23-pin AMPSEAL connector and is constructed using automotive-grade, high-temperature wire for durability in harsh environments. Each wire is color-coded and printed with its signal name to simplify installation, reduce errors, and support clean, professional wiring layouts.

Perfect for:

• Custom engine swaps

• Standalone ECU projects

• Race car rewiring

• Retrofit EFI conversions

Key Features:

• 8′ flying lead harness for MS3Pro ULTIMATE’s black center connector

• 23-pin AMPSEAL connector (pre-installed and sealed)

• Color-coded, printed wire labels for easy identification

• High-temp automotive-grade wire for long-term durability

• Supports advanced features like VVT, traction control, and flex fuel

• Designed for clean installs, upgrades, and system expansions

Note: This listing includes the center harness only. It is ideal for users who already have the main harness and want to unlock additional I/O on the MS3Pro ULTIMATE ECU.